Pallet head loader

ABSTRACT

A gripping head of the type designed to be attached to the free end of a lifting boom structure and configured to grip, position, empty and release containers wherein the head comprises a pair of movably mounted lifting arms arranged in opposed aligned relation to one another and wherein each arm includes quick release means in the form of a plate means movably mounted relative to gripping flanges formed on the ends of the lifting arms. A first fluid actuator piston and cylinder assembly is interconnected directly between the arms whereupon actuation of this first assembly causes the arms to extend and retract so as to grip and release containers. A head orienting means in the form of a second piston and cylinder assembly is interconnected between the frame and a rack and pinion gear wherein the rack is slidingly arranged relative to the frame and the pinion is attached to a support shaft whereupon actuation of this second assembly rotation of the head occurs through inner action of the rack and pinion.

ilnited Sttes atet [191 Caylor et a1.

[ 1 Sept. 16, 1975 PALLET HEAD LOADER [73] Assignee: Transcinor, Inc., Miami, Fla.

[22] Filed: July 5, 1973 [21] Appl. N0.: 376,690

Related [15. Application Data [63] Continuation-impart of Ser. No. 249,405, May 1,

1972, abandoned.

[52] US. Cl 294/67 R; 294/67 BB; 294/88 [51] int. Cl. B66C 1/66 [58] Field of Search 294/67 R, 67 B, 67 BB,

294/67 C, 67 D, 67 DA, 67 DC, 81 R, 81 SF, 88; 214/147 G, 302, 313, 314

Primary Examiner-Even C. Blunk Assistant Examiner.l0hnny D. Cherry Attorney, Agent, or Firm-Stein & Orman 5 7 ABSTRACT A gripping head of the type designed to be attached to the free end of a lifting boom structure and configured to grip, position, empty and release containers wherein the head comprises a pair of movably mounted lifting arms arranged in opposed aligned relation to one another and wherein each arm includes quick release means in the form of a plate means mov ably mounted relative to gripping flanges formed on the ends of the lifting arms. A first fluid actuator piston and cylinder assembly is interconnected directly between the arms whereupon actuation of this first assembly causes the arms to extend and retract so as to grip and release containers. A head orienting means in the form of a second piston and cylinder assembly is interconnected between the frame and a rack and pinion gear wherein the rack is slidingly arranged relative to the frame and the pinion is attached to a support shaft whereupon actuation of this second assembly rotation of the head occurs through inner action of the rack and pinion.

10 Claims, 7 Drawing Figures PALLET HEAD LOADER This application is a continuationin-part application of presently co-pending application Ser. No. 249,405, filed May 1, 1972, now abandoned.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a loading head used to load and unload a pallet or similar container whereupon the container is capable of being gripped, lifted, rotated and replaced in a desired position. The head is intended to be attached to a lifting boom or like structure.

2. Description of the Prior Art In the harvesting of fruit such as oranges, tomatoes or like agricultural products; fruit after being picked, is placed in large containers and arranged in predetermined locations in the field. A main storage and transportation vehicle travels between these pre-determined locations, picks up the containers loaded with fruit, and transports the fruit into a main hopper or the like on the vehicle itself. It of course has long been recognized that the handling of these agricultural products in the most efficient manner would result in time saved and thereby lower the cost of harvesting these products which in turn means larger profits to the producer of these agricultural products.

Accordingly, there has been a constant effort on the part of manufacturers of harvesting equipment to aid the farmer or agricultural producer in lessening his costs by providing the most efficient equipment to accomplish specified needs. In accord with this attempt to modernize and make more efficient harvesting equipment, various hi-lift and dumping mechanisms have been devised specifically for the picking up of containers and transferring the agricultural products from the containers to a transporting and storage vehicle, as set forth above. Along these lines various lifting or dumping heads have been designed and are presently commercially available.

Such a device is disclosed in U.S. Pat. No. 3,447,705 to Stone. As disclosed in FIGS. 5 and 6 of this patent a dumping head has been designed which is primarily intended to be attached to a free end of a lifting boom which itself is a part of a dump truck or like storage and transporting vehicle.

The problems prevalent in this particular industry have frequently arisen due to the fact that the particular need of the farmer or agricultural producer are specialized and specific. Accordingly, an attempt to overcome these specific problems by producers devising machines which are unduly complicated and accordingly expensive while at the same time not giving the farmer the versatility which is required for his needs. Of course, it can be readily seen that this versatility is directly associated with the performance capabilities of a lifting head. Specifically, referring to the operation of a lifting head, it is important that such a head be designed to be quickly and easily oriented relative to a container to be handled, while at the same time such orientation of the head require a minimum amount of operator time and attention. In addition, the accurate and rapid location of a pallet being unloaded is often dependent on accurate gripping of the pallet and also efficient, quick release thereof when the pallet is in the desired location. To accomplish this, a head structure design should be capable of being oriented at almost any desired position so as to facilitate gripping, lifting,

rotating, relocating and efficient releasing of the container as desired.

Based on the above, it can be seen that there is a great need in the harvesting equipment industry for a loading head which is capable of high-quality durable performance while at the same time being of simple structure which is easy to operate and maintain.

SUMMARY OF THE INVENTION This invention relates to a gripping head of the type used to be attached to a lifting boom or like structure and more specifically of the type which is capable of being associated with a transporting and storage vehicle associated with the harvesting of various agricultural products such as tomatoes, oranges and the like. As stated above, while the particular head structure disclosed herein is designed to be primarily used with a lift boom, it is obvious that the subject head structure could be used with various other types of booms or other lifting structure and accordingly the structural detail of the boom disclosed is not specifically a part of this invention.

The lifting head comprises two lifting arms arranged in opposed substantially aligned relation to one another along a common axis. Each of the arms are mounted in telescopic relation to substantially correspondingly configured, hollow sleeves. The sleeves themselves comprise part of a support frame. Located at the free end of each arm are gripping means each of which comprise at least one depending flange having an inwardly directed lip on the lower inside extremity thereof. The gripping means further includes pallet quick release means which may be in the form of a plate movably mounted adjacent each outward extremity of each arm. More specifically the release plate is disposed on the interior of each of the depending flanges and on the interior surface thereof. Each release plate is attached to a collar, which in turn movably engages and at least partially surrounds the corresponding arm on which the adjacently positioned re lease plate is mounted. The collar is attached to an elongated finger which is oriented above both the arm and sleeve to whichit is attached. Immediately adjacent to the collar and on the underside of the elongated finger is a riser means which has an angled or bevelled edge oriented to engage the outer most lip of the sleeve. Accordingly, as the arm is moved inward to the point where the lip of the sleeve engages the bevelled leading edge of the riser means, the riser means is forced upwardly onto the upper surface of the sleeve thereby forcing the release plate to also rise. A spacer block is located on the interior surface of the release plate and is oriented either to engage the interior surface of the gripping flange or alternately to be positioned in a slot or aperture formed in the flange. When the spacing block is arranged against the interior surface of the flange, the release plate is essentially flush with the leading edge of the lip which is attached to the lower extremity of the flange. In this position, the plate forces disconnection between the flange and any pallet or box which was engaged by the gripping head. This prevents hang-up when the head is being removed from one or more pallets loaded in close proximity to one another. Alternately, when the block is positioned within the slot of the flange, as when the plate is in its upper position, the plate is spaced away from the lip of each flange so that this lip is clear to engage the outwardly extending rim of the container or pallet being gripped by the head. Accordingly, the position of the release plate is dependent upon the degree of extension of the arms away from or out of the supporting sleeves in which they are slidingly mounted. Inward movement of the arms causes engagement between the riser and the lip of the sleeve causing the plate to move up into its non-release position thereby allowing the lip to be free to engage the rim of the container. Outward movement or extension of the arms out of the sleeve causes disengagement between the riser and the upper surface or lip of the sleeve thereby allowing the release plate to slide downwardly into flush relation to the leading edge of the lip and in spaced position from the interior surface of the flange. This causes release of the outwardly projecting lip from the container.

Arrn extending means in the form of a first fluid actuated piston and cylinder assembly is mounted in direct interconnecting relation between the two arms. Actuation of this first assembly which causes the relative movement of the piston and cylinder element in turn causes the extension or retraction of the arm relative to the support frame. An important feature of the present invention is that this first assembly is free floating in the sense that the piston and cylinder assembly is connected only to the arms themselves and is not mounted in supporting relation to the frame of the head. Stop means comprising slots formed directly in the sides of the sleeves are provided with specific, predetermined lengths such that the portions of the first assembly engaging the arms, do so through these slots and the amount of extension of the piston and cylinder assembly is limited by the length of these slots. The extremities of each slot is arranged in abutting relation to the portion of the first assembly directly joined to the respective arm of the head. Conduit or fluid supply lines are of course interconnected between a control panel located at the operator position and the first piston and cylinder assembly.

Head orienting means comprises a second, fluid actuated piston and cylinder assembly and is interconnected between the frame of the head and the support shaft on which the head is mounted. More specifically, one end of the second assembly is attached to at least one of the sleeves while the other end is directly connected to a rack and pinion. The rack element of the rack and pinion assembly is slidingly mounted on the frame in a rack sleeve so as to move .in a reciprocal path substantially parallel to the longitudinal axis of the arms and sleeves in which they are mounted. The rack of course is in direct meshing relationship to the pinion element of the rack and pinion assembly. This pinion is fixedly attached to the support shaft such that relative movement between the rack and the pinion causes rotation of the head about the support shaft, thereby aiding in the orientation of the head relative to a container which is to be handled.

The invention accordingly comprises the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereinafter set forth and the scope of the invention will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS For a fuller understanding of the nature and objects of the present invention, reference will be had to the following detailed description taken in connection with the accompanying drawings in which:

FIG. 1 is a basic schematic view of the head of the subject invention attached to a lifting boom andcontainer or like device with which the head is designed to be utilized.

FIG. 2 is a top sectional view taken along lines 2-2 of FIG. 1 showing the details of the head structure.

FIG. 3 is a side, partial cutaway view of the head structure including the rack and pinion assembly mounted thereon.

FIG. 4 is a sectional view taken along line 44 of FIG. 3 showing details of the rack and pinion assembly.

FIG. 5 is a detailed view of the operation and location of the release plate.

FIG. 6 is a detailed, partial cutaway view of the release plate in its release position.

FIG. 7 is an end view of the depending flange attached to each of the lift arms of the present invention.

Similar reference characters refer to similar parts throughout the several views of the drawings.

DETAILED DESCRIPTION This invention relates to a gripping head generally indicated as 10 in FIG. 1. As shown therein the head is designed to be attached to a lifting boom generally indicated at 12 which comprises a support 14, pivot base 16, plurality of actuators l8 and 19 and pivot arms 20 and 22. Directional arrows 24 show the various movements of the lifting boom wherein actuating cylinder assembly 18 causes pivotal movement between boom arm 20 and base 16 about pivot point 26. Similarly, actuating cylinder 19 causes relative pivotal motion of boom arm 22 about pivot point 28 due to link members 30. A support shaft 32 interconnects the frame 10 to the remaining part of the boom structure in supporting relation thereto.

With specific reference to FIGS. 2 and 3 the head comprises a pair of lifting arms 34 and 36 arranged in opposed substantially aligned relation to one another along a substantially common longitudinal axis. Sleeve means in the form of hollow, correspondingly configured tubular members 38 and 40 comprise a portion of the support frame of the head and are disposed so as to have arms 34 and 36 respectively mounted therein in telescopic relation thereto.

Gripping means in the form of depending flanges 42 and 44 are aranged at the free extremity of each arm 34 and 36 respectively. These flanges may be welded to the appropriately located extremities of the arms or attached in any other applicable manner so as to extend substantially perpendicular to the longitudinal axis of the lifting arms. At the lower inside extremity of each flange 42 and 44 is located an inwardly extending lip 46 and 48. With reference to FIG. 1 the flange and lip formed thereon is positioned relative to a rim 50 of container 52 so that the container may be lifted, rotated, or otherwise handled as desired in order to orient the container as desired.

An arm extending means generally indicated as 54 is arranged in free-floating" direct interconnecting relation between arms 34 and 36. More specifically the arm extending means comprises a first. fluid actuated piston and cylinder assembly comprising piston 56 and cylinder 58. As shown in FIG. 2, the free end of piston 56 is connected directly to a flange 60 which in turn is attached to connector bracket 62. Similarly, the opposite end of the assembly, namely the free end of cylinder 58 has bracket 64 mounted thereon which in turn is attached to connector bracket 66. Connecting point 68 and 70 may be capable of pivotal movement thereby allowing relative movement between flanges and bracket 60, 62, 64 and 66 respectively. This relative movement may be allowed if needed depending on the particular application on the head. The brackets 62 and 66 are connected directly to arms 34 and 36 respectively through stop means in the form of specifically configured slots 70 and 72. These slots are formed directly in the sides of sleeves 38 and 40 and their lengths at least partially determine the length of stroke and degree of extension of the piston and cylinder assembly 54. This is due to the fact that surfaces 74, 76 and 78, 80 of brackets 62 and 66 respectively abut against the extremity of the slots 70 and 72. The relative movement between piston 56 and cylinder 58 occurs along the longitudinal axis of the piston and cylinder assembly and is indicated generally by directional arrow 82. Similarly, the direction of extension and retraction of lifting arms 34 and 36 occurs along the longitudinal axis of these arms and is indicated by directional arrow 84. Fluid communication to the interior of cylinder 58 occurs at two locations, 86 and 88 which are positioned on opposite sides of a piston head (not shown) attached to the piston 56 on the interior of cylinder 58. The flow of fluid into and out of the cylinder through these ports of course determines the extension or retraction of the piston and cylinder assembly as is conventionally practiced in the art.

This invention also comprises a quick release means in the form of a release plate 51 and 53 which are movably positioned immediately to the interior surfaces 55 and 57 of flanges 42 and 44 respectively. In that the structure of each of the plates 51 and 53 are essentially the same and their relation and cooperation with flanges 42 and 44 operate in essentially the same manner, the following description will be directed to the structure and operation of flange 51 only, for the purpose of clarity. With reference to FIGS. 3, 5, 6 and 7, the plate 51 is movable relative to flange 42 due to its connection to elongated finger member 59 secured to the uppermost portion of plate 51 as shown in FIGS. 5 and 6. A collar 61 is attached to the plate 51 and serves to partially enclose and is also movably mounted relative to the correspondingly positioned arm 34 which it engages. As shown in FIG. 3, each of the elongated fingers 59 associated with the respective plate 51 and 53 are movably mounted relative to the sleeves 38 and 40 in which the arms 34 and 36 travel. This connection is in part due to the fingers 59 being slideably mounted on the interior of strap 63 attached to each of the sleeves as shown in FIGS. 2 and 3. Stop means 65 are attached to the opposite extremities of fingers 59 as shown and are oriented to engage the extremities 67 of the strap 63 for the purpose to be described hereinafter. A spacer block 69 is provided on the interior surface 71 of each of the plates 51 and 53 as shown. In ad dition, riser means 73 are provided on the undcrsurface of fingers 59 and are specifically positioned to engage the uppermost and outermost edge 75 of each of the sleeves 38 and 40. It is also important to note that each of the riser means 73 has an angled or bevelled leading edge 77 which itself is particularly oriented to engage this leading edge 75.

With specific reference to FIGS. 5 and 6 the inward movement of arm 34 relative to sleeve 38 causes engagement between angled or bevelled edge 77 and leading edge of the riser and sleeve respectively. This, in turn forces the riser to travel upon the upper surface 79 of sleeve 38 which, in turn, causes plate 51 to rise and block 69 to be forced within slot 81 formed in each of the flanges 42 and 44. In this position, the block 69 will ride on the base of slot or groove 81 thereby allowing the interior surface 71 to be positioned in engagement with the interior surfaces of each of the flanges 42 and 44 as shown in FIG. 5. This may be considered the non-release position of plate 51 in that it is spaced away from gripping lip 46 thereby allowing it to engage the rim 50 as described above.

Continued outward extension or movement of the arms relative to their sleeve causes the elongated finger 59 and more particularly the stop member 65 thereon to engage th extremity 67 of each of the straps 63. This forces the block 69 to be removed from the slots 81 thereby causing the respective plates 51 and 53 to engage the lips 46 and 48 in a substantially flush relationship thereto as shown in FIG. 6. The blocks 69 are arranged in spaced relation between the interior surfaces of the flanges and the respective release plates attached therewith. This may be considered the released position of each of the plates since movement of the plate into this flush position relative to their respective lips 46 and 48 forces the flanges away from an unattached relation to the rim 50 of the containers. This, of course, prevents a hang up during the removal of the head from the containers when such containers are arranged in relatively close proximity to a number of other containers.

A head orienting means generally indicated in FIG. 2 as and comprises a second fluid actuating piston and cylinder assembly including piston 92 and cylinder 94. The free end of cylinder 94 has flange 96 formed thereon which is attached directly to the connector bracket 98 by connection 100. Similarly, the opposite end of piston 92 has flange 102 formed thereon which in turn is connected to connector bracket 104 at connection 106. This second assembly 90 is interconnected between the frame of the head and support shaft 32. More specifically, connector bracket 98 is formed on the outer surface of sleeve 40 while the connector bracket 104 is attached directly to a rack and pinion assembly shown in FIG. 4. The rack element 108 of the rack and pinion assembly is slidingly mounted within rack housing 1 10 and is oriented therein to move along its own longitudinal axis by virtue of the relative movement between piston 92 and cylinder 94. Rack 108 has gear teeth 112 formed on at least one longitudinal side thereof which are disposed to meshingly engage the teeth 114 of pinion gear 116. Pinion 116 is fixedly attached to support shaft 32 such that relative movement between rack 108 and pinion 116 causes the rotation of the head 10 about the support shaft 32. Bearing 118 is arranged between an outer bushing 120 and the exterior surface of the support shaft 32. A second bushing or washer structure serving as a spacer 122 is positioned immediately above the pinion 1 16 as best shown in FIG. 4. At its upper end, support shaft 32 is attached to the boom arm extremity by means of saddle bracket 132 joined by connecter 134 and arranged to pivot around axis 136. Sleeve bushing 138 is designed to fit over the upper portion of support shaft 32 and be connected thereto by a screw threaded fastener or like connector means 140.

Referring back to the second piston and cylinder assembly 90, fluid communication ports 91 and 93 are similarly positioned so as to pass fluid to and from the interior of cylinder 94 thereby controlling the position of a piston head (not shown) attached to piston 92 on the interior of cylinder 94.

It will thus be seen that the objects set forth above among those made apparent from the preceding description, are efficiently attained and since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention, which as a matter of language might be said to fall therebetween.

Now that the invention has been described, what is claimed is:

l. A gripping head of the type connected to a boom mechanism and designed to load and position containers or the like, said head comprising: a head frame; a pair of lifting arms connected to said frame: gripping means connected adjacent the outer ends of each arm: release means movably mounted on said head adjacent said gripping means and movable between a release and a non-release position, said release means comprising release plate means movably mounted on said frame relative to said gripping means, riser means connected to said release plate means and positioned to movably engage said frame upon movement of said one arm, whereby engagement of said riser and said frame causes movement of said plate means relative to said gripping means; at least one of said arms slidingly engaging said frame and movably arranged relative to said other arm; arm extending means mounted on said frame and connected at least to said one arm; and a support shaft interconnecting said head to the boom, whereby actuation of said arm extending means causes positioning of said head relative to a container being loaded.

2. A lifting head as in claim 1 wherein said arm extending means is interconnected between said two arms independent of direct engagement with said frame, both of said arms arranged in sliding engagement with said frame such that actuation of said arm extending means causes simultaneous movement of both said arms relative to said frame.

3. A lifting head as in claim 2 wherein said arm extending means comprises a fluid actuated first piston cylinder assembly, said first piston cylinder assembly connected at one end to one of said pair of arms and said first piston cylinder assembly connected at its opposite end to the other of said arms, whereby fluid actuation of said first piston cylinder assembly causes simultaneous movement of said arms.

4. A gripping head as in claim 3 further comprising head orienting means connected to said frame and operatively positioned relative to said shaft, said head orienting means comprising a rack and pinion assembly disposed in alignment with the longitudinal axis of said arms, said pinion of said assembly mounted on said support shaft in engagement with said rack, whereby relative movement of said rack and pinion causes movement of said head relative to a boom on which it is mounted.

5. A gripping head as in claim 4 wherein said head orienting means further comprises a second fluid actuator piston and cylinder assembly, said second assembly interconnected between said rack and said frame, whereby actuation of said second assembly causes rota tion of said head relative to said support shaft.

6. A gripping head as in claim 5 wherein said frame comprises at least a pair of sleeves having a corresponding configuration to said arms, each of said arms slidingly positioned within one of said sleeves, said second piston cylinder assembly interconnected between said rack and said one sleeve.

7. A gripping head as in claim 6 wherein said arm extending means comprises a first piston and cylinder assembly interconnected between said arms, stop means comprising slots formed in each of said sleeves through which said first assembly connects said arms, said slot arranged in abutting relation to said first assembly so as to determine the length of extension of said arm when said first piston and cylinder assembly is actuated.

8. A gripping head as in claim 3 wherein each of said arms is slidingly mounted within a sleeve, stop means formed on at least one of said sleeves and disposed in abutting relation to a cooperatively positioned end of said first cylinder piston assembly, whereby the amount of extension of said arms from said frame is at least partially determined by the position of said stop means.

9. A gripping head as in claim 1 wherein said release means further comprises spacer block means positioned between said release plate and said gripping means, said plate means movable into a release position defined by being arranged in substantially adjacent spaced relation thereto, said plate means movable into a non release position defined by said plate arranged in movable direct engagement with said gripping means.

10. A gripping head as in claim 1 wherein said gripping means comprises depending flange means connected to a free end of each of said lifting arms, lip means mounted on each of said depending flange means and extending outwardly therefrom, said release plate means including at least one plate element movably mounted adjacent each of said depending flange means and positionable in substantially flush relation to said correspondingly disposed lip means, whereby said relative flush orientation defines said release position. 

1. A gripping head of the type connected to a boom mechanism and designed to load and position containers or the like, said head comprising: a head frame; a pair of lifting arms connected to said frame: gripping means connected adjacent the outer ends of each arm: release means movably mounted on said head adjacent said gripping means and movable between A release and a nonrelease position, said release means comprising release plate means movably mounted on said frame relative to said gripping means, riser means connected to said release plate means and positioned to movably engage said frame upon movement of said one arm, whereby engagement of said riser and said frame causes movement of said plate means relative to said gripping means; at least one of said arms slidingly engaging said frame and movably arranged relative to said other arm; arm extending means mounted on said frame and connected at least to said one arm; and a support shaft interconnecting said head to the boom, whereby actuation of said arm extending means causes positioning of said head relative to a container being loaded.
 2. A lifting head as in claim 1 wherein said arm extending means is interconnected between said two arms independent of direct engagement with said frame, both of said arms arranged in sliding engagement with said frame such that actuation of said arm extending means causes simultaneous movement of both said arms relative to said frame.
 3. A lifting head as in claim 2 wherein said arm extending means comprises a fluid actuated first piston cylinder assembly, said first piston cylinder assembly connected at one end to one of said pair of arms and said first piston cylinder assembly connected at its opposite end to the other of said arms, whereby fluid actuation of said first piston cylinder assembly causes simultaneous movement of said arms.
 4. A gripping head as in claim 3 further comprising head orienting means connected to said frame and operatively positioned relative to said shaft, said head orienting means comprising a rack and pinion assembly disposed in alignment with the longitudinal axis of said arms, said pinion of said assembly mounted on said support shaft in engagement with said rack, whereby relative movement of said rack and pinion causes movement of said head relative to a boom on which it is mounted.
 5. A gripping head as in claim 4 wherein said head orienting means further comprises a second fluid actuator piston and cylinder assembly, said second assembly interconnected between said rack and said frame, whereby actuation of said second assembly causes rotation of said head relative to said support shaft.
 6. A gripping head as in claim 5 wherein said frame comprises at least a pair of sleeves having a corresponding configuration to said arms, each of said arms slidingly positioned within one of said sleeves, said second piston cylinder assembly interconnected between said rack and said one sleeve.
 7. A gripping head as in claim 6 wherein said arm extending means comprises a first piston and cylinder assembly interconnected between said arms, stop means comprising slots formed in each of said sleeves through which said first assembly connects said arms, said slot arranged in abutting relation to said first assembly so as to determine the length of extension of said arm when said first piston and cylinder assembly is actuated.
 8. A gripping head as in claim 3 wherein each of said arms is slidingly mounted within a sleeve, stop means formed on at least one of said sleeves and disposed in abutting relation to a cooperatively positioned end of said first cylinder piston assembly, whereby the amount of extension of said arms from said frame is at least partially determined by the position of said stop means.
 9. A gripping head as in claim 1 wherein said release means further comprises spacer block means positioned between said release plate and said gripping means, said plate means movable into a release position defined by being arranged in substantially adjacent spaced relation thereto, said plate means movable into a non release position defined by said plate arranged in movable direct engagement with said gripping means.
 10. A gripping head as in claim 1 wherein said gripping means comprises depending flange means connected to a free end of each of said lifting arms, lip means mOunted on each of said depending flange means and extending outwardly therefrom, said release plate means including at least one plate element movably mounted adjacent each of said depending flange means and positionable in substantially flush relation to said correspondingly disposed lip means, whereby said relative flush orientation defines said release position. 